Chapter 6 - Ion Plating

Abstract

Ion plating is a physical vapor deposition (PVD) process that utilizes concurrent or periodic bombardment of the substrate and depositing atoms of film material by atomic-sized energetic particles. The bombardment prior to deposition, sputter cleans the surface. Bombardment during deposition is to obtain good adhesion, densify the depositing material, aid in chemical reactions, modify residual stress, and otherwise modify the structure, morphology, and properties of the depositing film or coating. Ion plating is also called ion assist (IA) deposition, ionization assisted deposition (IAD) or ion vapor deposition (IVD). Bombardment prior to deposition is used to sputter clean the substrate surface. Bombardment during the initial deposition phase can modify the nucleation behavior of the depositing material such as the nucleation density and interface formation. During deposition the bombardment is used to modify and control the morphology and properties of the depositing film. It is important that the bombardment be continuous between the cleaning and the deposition portions of the process in order to maintain an atomically clean interface. In ion plating the energy, flux and mass of the bombarding species along with the ratio of bombarding particles to depositing particles, are important processing variables. The depositing material may be vaporized by evaporation, sputtering, or arc vaporization, or by decomposition of a chemical vapor precursor (chemical ion plating (CIP)). Ion plating can also be done using periodic bombardment if the deposit build-up between bombardment cycles is small. Ion plating can be done in a plasma environment. Densification by bombardment with atomic sized particles is often called atomic peening.